Cattle producers “know that they and their pets can get tick bites, but often they forget that their livestock may be equally or more vulnerable to ticks,” says Rebecca Trout Fryxell, Ph.D. associate professor of medical and veterinary entomology at the University of Tennessee. Trout Fryxell and graduate student David Theuret recently conducted a study that found ticks on about one in six cattle in Tennessee. (Photo credit: Rebecca Trout Fryxell, Ph.D.)

For livestock producers unconcerned about ticks, a new study on cattle in Tennessee could provide a wake-up call.

In a two-year project, researchers at the University of Tennessee (UT) sampled cattle for ticks at livestock auctions, university research and education centers, and farms across the state in 2015 and 2016, and they found about one in six animals was carrying ticks. By far the most common tick species found was the lone star tick (Amblyomma americanum), followed by the Gulf Coast tick (Amblyomma maculatum) and the American dog tick (Dermacentor variabilis).

“None of the cattle were severely infested, but ticks were found on at least some cattle at more than three-quarters of sampling locations and in all regions of the state. That might come as a surprise to livestock producers,” says Rebecca Trout Fryxell, Ph.D., associate professor of medical and veterinary entomology at UT and senior author on the study, published last week in the Journal of Medical Entomology. “Ticks are a hidden health threat and economic expense to the cattle industry. Producers know that they and their pets can get tick bites, but often they forget that their livestock may be equally or more vulnerable to ticks,” Trout Fryxell says.

Ticks can threaten livestock in multiple ways. Ticks can cause damage via their bites, and in some cases can transmit infectious agents to animals. Fortunately, two of the most lethal tick-borne livestock diseases, Bovine Babesiosis and Heartwater, are not currently present in the United States, but potential introductions are an ongoing concern.

When ticks feed on cattle, they often nestle under the ears. While in some cases ticks can transmit infectious pathogens to cattle, they can also cause damage via their bites, such as necrosis of ear tissue and a condition known as “gotch ear.” (Photo credit: Rebecca Trout Fryxell, Ph.D.)

David Theuret, a graduate student in Trout Fryxell’s lab at the time of the study (now an entomologist at the Arkansas Department of Health), led the research project. Theuret coordinated the participation of six livestock auction sites and nine UT extension agents working with 21 producers, in addition to three UT research and education centers, all with a primary goal of raising awareness of ticks in the cattle industry by highlighting their presence. “The perceived risk from ticks needs to change so that it is commonly accepted that they can cause serious health impacts to cattle if not managed properly. This will be critical for getting stakeholders in the cattle industry to consider adopting more active surveillance at auctions to help against current and invasive tick threats,” Theuret says.

To that end, the researchers say their project offers a model for—as they put it in the title of their report—”beefing up biosecurity.”

“I really like the idea of personnel, perhaps veterinarians or an animal technician, checking cattle for ticks at auctions or when animals are moving between herds, especially since most of the infrastructure is already there,” says Trout Fryxell. “It’s a simple solution that can prevent further tick movement and establishment. It’s very likely that producers that use closed-herd procedures will have fewer ticks. Closed herd procedures include planning ahead when a producer purchases an animal, how many animals, and where those animals originate and implementing a quarantine period and location before animals are introduced to a herd.”

Increased awareness of ticks would lead to producers requesting tick checks more often before purchasing cattle and regular surveillance. Continued surveillance would both improve the screening of cattle for ticks and build a deeper set of data on seasonal and geographic patterns of tick presence in the state—or in any other state that followed such a model.

“We hope that this research, in combination with the recent discoveries of the invasive longhorned tick [Haemaphysalis longicornis] in multiple states in the U.S., spurs further interest and research into the tick-borne threats of cattle and other livestock,” says Theuret.